Everyone knows that President Obamahas a problem with his political base heading into 2012. Except that he doesn’t.

One of the most persistent story lines for the president has been that the liberal left has grown increasingly dissatisfied with his actions (or inaction) on some of its priorities — including single-payer health insurance, the extension of the George W. Bush tax cuts and whether to close the military prison at Guantanamo Bay, Cuba.

But an examination of the polling data among key subgroups that constitute Obama’s base makes clear that he has as much support from them as any modern president seeking a second term.

“There is one immutable fact about President Obama’s reelection chances: Nobody has a more solid 44 percent base than he does,” Democratic pollster Peter Hart wrote in a not-entirely-uncritical memo assessing the state of political affairs a year out from the election.

<<snip>>

At the heart of the president’s enduring strength among his base are African Americans who have never wavered in any meaningful way after 95 percent of black voters opted for the Illinois senator in 2008.

<<snip>>

Given that African Americans made up 13 percent of the overall electorate in 2008 — and, hence, a much larger chunk of the Democratic base vote — Obama’s continued support among that key demographic makes any sort of widespread base erosion in 2012 unlikely.